a 
forte abrupta, cinerea, ad margines flavescens, margine 
postico et infero forte arcuatis, anteriore curvato; um- 
bones parum prominentes, obtusi, uterque vesica de- 
pressa striata mamillatus.. — L. 3, diam.. 2?],, crass. 
2 mm. 
Port Clarence. 
Pisidium nivale n. 
Concha ovalis, compressissima, tenuis, parum inaequilatera, 
postice late rotundata, anticerotundato-acuminata, cinerea, 
striata, vix nitidula, marginibus acutis; umbones minu- 
tissimi, albidi, marginem superiorem non superantes. — 
Long. 3"), lat. 3, er. 11, mm. 
Port Clarence, 
Pisidium glaciale n. 
Concha ovata, valde ventricosa, inaequilatera, cinerea, dense 
striata et suleis pluribus profundiuseulis notata; umbones 
rotundati, prominentes, inflati, cum natibus convexis 
dense regulariter striati. — Long. 3'J,, diam. 3!],, er. 
21), mm. 
Port. Clarence. 
Cyrena crebricostis n. 
©oncha trigona, inaequilatera, latere antico breviore rotun- 
dato, postico substricto cum margine inferiore angu- 
lum perobtusum formante, ventricosa, crassa, solidis- 
 sima, epidermide nitida, flavescente, medio piceata, costis 
densis numerosis (c. 40), superne abruptis usque ad api- 
cem regulariter munita; umbones validi, tumidi, obtusi, 
conniventes; margarita pallide coerulescens; dentes car- 
-dinales et laterales validisimi. — Lat. 25, alt. 26, 
crass. 17 mm. 
China, Hongkong. 
